Crop Biotech Update

Scientists Investigate the Levels of Control of Stem Borer in Bt maize in Kenya

June 10, 2011

According to reports, stem borers (Chilo partellus) destroy about 400,000 metric tons of maize in Kenya, which is about 13.5% of the farmer's annual harvest. Farmers have used Bacillus thuringiensis (Bt) maize to control the spread of stem borers. Mwimali Murenga of Kenya Agricultural Research Institute, crossed two Bt maize lines (Events 216 and 223) with two non-Bt maize inbred lines (CML144 and CML159) and investigated the efficacy of the parents and successive generations in controlling of stem borers.

Results showed that the Bt gene effectively lessened the damage caused by stem borers by comparing the damage in Bt lines, non-Bt maize, and controls. This was measured by number of exit holes, tunneling length, proportion of stalk tunneled number of larvae and number of pupae. The damage in the first generation of crossed lines were comparable with the Bt inbred lines. On the other hand, the following generations exhibited more damage from resistant to susceptible. This may imply that the Cry1Ab genes in the study was inherited according to Mendelian segregation.

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